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order of execution of page_load in a base and derived classes

Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" / derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before the
base?

is this also the order of execution in inheritence or only with delegated
event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.
Nov 21 '05 #1
11 1024
Hi,

I have never been in this situation, but the first thing I would try is in
the Form.OnInit move the base.OnInit to the start of the method, before
register the Load handler for the current page.

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the original System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" / derived page gets to be executed.

but i have noticed that the derived page load event gets to be called before the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like button) event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before the base?

is this also the order of execution in inheritence or only with delegated
event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.

Nov 21 '05 #2
Please don't cross-post.

I'm assuming you are using C# 'cuz you wouldn't have this behaviour in
VB....anyways, the simplest solution is to go into your derived page's
OnInit function in the "Web Form Designer generated code" region, and change
the order of the two executions:

InitializeCompo nent();
base.OnInit(e);

to

base.OnInit(e);
InitializeCompo nent();

This will cause the base page's init to load first, which will cause it's
Load event to get hooked up first, thus causing it to fire first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the original System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" / derived page gets to be executed.

but i have noticed that the derived page load event gets to be called before the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like button) event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before the base?

is this also the order of execution in inheritence or only with delegated
event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.

Nov 21 '05 #3
Hi again

I'm not very sure that the previous answer will solve the problem, IIRC
the order of execution of the handlers is not defined. therefore even ify ou
register first the parent you may get the derived executing first after all.

Therefore you have to use another approach, you could use a virtual method
that you call in the OnLoad event, so each class Page) define what needs to
be checked , being the trick to verify the parent first to have the first
line calling the parent method:
protected override Check()
{
parent.Check();
//do the checking
}

I think this will solve your problem.
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the original System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" / derived page gets to be executed.

but i have noticed that the derived page load event gets to be called before the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like button) event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before the base?

is this also the order of execution in inheritence or only with delegated
event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.

Nov 21 '05 #4
i use vb.net
and i don't override the OnInit method in my PageBase.

"Karl" <karl REMOVE @ REMOVE openmymind REMOVEMETOO . ANDME net> wrote in
message news:uP******** ******@TK2MSFTN GP09.phx.gbl...
Please don't cross-post.

I'm assuming you are using C# 'cuz you wouldn't have this behaviour in
VB....anyways, the simplest solution is to go into your derived page's
OnInit function in the "Web Form Designer generated code" region, and change the order of the two executions:

InitializeCompo nent();
base.OnInit(e);

to

base.OnInit(e);
InitializeCompo nent();

This will cause the base page's init to load first, which will cause it's
Load event to get hooked up first, thus causing it to fire first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before

the
base?

is this also the order of execution in inheritence or only with delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.


Nov 21 '05 #5
i wouldn't like to add code to each page-class i add.
the idea behind using a PageBase is to not change the way i write the other
pages, just let them use the services the PageBase implement without even
"knowing" anout it.
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:%2******** ********@tk2msf tngp13.phx.gbl. ..
Hi again

I'm not very sure that the previous answer will solve the problem, IIRC
the order of execution of the handlers is not defined. therefore even ify ou register first the parent you may get the derived executing first after all.
Therefore you have to use another approach, you could use a virtual method that you call in the OnLoad event, so each class Page) define what needs to be checked , being the trick to verify the parent first to have the first
line calling the parent method:
protected override Check()
{
parent.Check();
//do the checking
}

I think this will solve your problem.
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before

the
base?

is this also the order of execution in inheritence or only with delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.


Nov 21 '05 #6
We had the same problem with the Page_Load Event.

We solved it similar to the way Ignacio Machin describes using the OnLoad
event.

Good luck,

Benjamin Schwitter

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:#n******** ******@tk2msftn gp13.phx.gbl...
Hi again

I'm not very sure that the previous answer will solve the problem, IIRC
the order of execution of the handlers is not defined. therefore even ify ou register first the parent you may get the derived executing first after all.
Therefore you have to use another approach, you could use a virtual method that you call in the OnLoad event, so each class Page) define what needs to be checked , being the trick to verify the parent first to have the first
line calling the parent method:
protected override Check()
{
parent.Check();
//do the checking
}

I think this will solve your problem.
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before

the
base?

is this also the order of execution in inheritence or only with delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.


Nov 21 '05 #7
also

from the IL created by VB compiler you see that in the constructor it is
adding the event handler:

Public Sub New()
AddHandler MyBase.Load, New EventHandler(Ad dressOf Me.Page_Load)
End Sub

"Karl" <karl REMOVE @ REMOVE openmymind REMOVEMETOO . ANDME net> wrote in
message news:uP******** ******@TK2MSFTN GP09.phx.gbl...
Please don't cross-post.

I'm assuming you are using C# 'cuz you wouldn't have this behaviour in
VB....anyways, the simplest solution is to go into your derived page's
OnInit function in the "Web Form Designer generated code" region, and change the order of the two executions:

InitializeCompo nent();
base.OnInit(e);

to

base.OnInit(e);
InitializeCompo nent();

This will cause the base page's init to load first, which will cause it's
Load event to get hooked up first, thus causing it to fire first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the
class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called before

the
base?

is this also the order of execution in inheritence or only with delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.


Nov 21 '05 #8
Can you show me some code? If I do this:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Trace.Write("de rived load")
end sub

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Trace.Write("ba seload")
end sub

the base load always fires first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** *******@TK2MSFT NGP09.phx.gbl.. .
i use vb.net
and i don't override the OnInit method in my PageBase.

"Karl" <karl REMOVE @ REMOVE openmymind REMOVEMETOO . ANDME net> wrote in
message news:uP******** ******@TK2MSFTN GP09.phx.gbl...
Please don't cross-post.

I'm assuming you are using C# 'cuz you wouldn't have this behaviour in
VB....anyways, the simplest solution is to go into your derived page's
OnInit function in the "Web Form Designer generated code" region, and

change
the order of the two executions:

InitializeCompo nent();
base.OnInit(e);

to

base.OnInit(e);
InitializeCompo nent();

This will cause the base page's init to load first, which will cause it's
Load event to get hooked up first, thus causing it to fire first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called
before the
base?

is this also the order of execution in inheritence or only with

delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.



Nov 21 '05 #9
Hi,

IIRC the Page_Load is added in the OnInit handler:

override protected void OnInit(EventArg s e)
{
InitializeCompo nent();
base.OnInit(e);
}
private void InitializeCompo nent()
{
this.Load += new System.EventHan dler(this.Page_ Load);
}

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:eF******** ******@TK2MSFTN GP15.phx.gbl...
also

from the IL created by VB compiler you see that in the constructor it is
adding the event handler:

Public Sub New()
AddHandler MyBase.Load, New EventHandler(Ad dressOf Me.Page_Load)
End Sub

"Karl" <karl REMOVE @ REMOVE openmymind REMOVEMETOO . ANDME net> wrote in
message news:uP******** ******@TK2MSFTN GP09.phx.gbl...
Please don't cross-post.

I'm assuming you are using C# 'cuz you wouldn't have this behaviour in
VB....anyways, the simplest solution is to go into your derived page's
OnInit function in the "Web Form Designer generated code" region, and

change
the order of the two executions:

InitializeCompo nent();
base.OnInit(e);

to

base.OnInit(e);
InitializeCompo nent();

This will cause the base page's init to load first, which will cause it's
Load event to get hooked up first, thus causing it to fire first.

Karl

"z. f." <zi**@info-scopeREMSPAM.co .il> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..
Hi,

i have a class that is derived from System.Web.UI.P age, and this is the class i use in my application as PageBase.
all other page classes are deriverd from my PageBase instead of the

original
System.Web.UI.P age in order to have common checks in the page base.

i make securirty checks in the page base page_load event.
if the security fails, i can do whatever i want before the "real" /

derived
page gets to be executed.

but i have noticed that the derived page load event gets to be called

before
the base page load event.

so i have a problem.

i can cancel the use of page_load in my derived pages, but i use this
function to check on PostBack events that does not have server (like

button)
event handler, but there when will i move it to?

is this the correct execution order - the derived gets to called
before the
base?

is this also the order of execution in inheritence or only with

delegated event handlers? ( i mean when you use the syntax of Page.onLoad +=
this_onLoad )....

TIA, z.



Nov 21 '05 #10

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